Ignition On/Off, Basic Function - GF07.10-P-1039A

Engine all (4xWD) 

Engine all (CAR) 

Overview 

This document contains information on:

• General 
• Function requirements 
• Function 
  • Ignition ON 
  • Ignition OFF 

General 

The ignition ON function starts the engine management in the combustion engine control unit and prepares the combustion engine for starting.

The ignition OFF function switches off the combustion engine and then the engine management in the combustion engine control unit.

Function requirements 

• Ignition ON (circuit 15)

Function 

Ignition ON 

If the ignition is switched on, the electronic ignition lock control unit switches on the circuit 15 relay. Via the conducted on-board electrical system voltage, the engine management in the combustion engine control unit is started. The circuit status is also available to other systems via the vehicle bus systems.

The following functions will start if the ignition is switched on and the engine management is started:

• To fully fill the low-pressure fuel circuit and build up pressure, the fuel pump will briefly be actuated the first time the ignition is switched to ON and after the vehicle has been unlocked.
• Engine diagnostics indicator lamp actuated on the instrument cluster.
• In the case of diesel engines: preglow indicator lamp actuated on instrument cluster as well as glow output stage.
• Fault memory in combustion engine control unit can be read out and deleted via the diagnostics connection.
• Diagnosis or correction programming can be performed via the diagnostics connection.
• Throttle valve actuator checks its return spring and performs an actuator adaptation if necessary.

Ignition OFF 

Additional function requirements:

• Engine management ON (circuit 87M)

If the ignition is switched off, the electronic ignition lock control unit switches off the circuit 15 relay. The circuit status is also available to other systems via the vehicle bus systems.

The following components are switched off if the ignition is switched off:

• Fuel pump (FP)
• Fuel injectors
• Quantity control valve
• With spark-ignition engines: ignition coils

The computer run-on of the combustion engine control unit also starts. In this connection, the time until the control unit changes to standby mode is involved.

	Function schematics
	Function schematic for ignition ON	Engine 260, 282, 608 in model 118, 177, 247 Engine 264 in model 167	PE07.10-P-2505-97A
		Engine 176, 177 in model 167 Engine 177 in model 290 as of model year 2021	PE07.10-P-2505-97B
		Engine 274 in model 213 as of model year 2021	PE07.10-P-2505-97C
		Engine 654 in model 118, 167, 177, 247 Engine 654 in model 213, 238, 257 as of model year 2021 Engine 656 in model 167	PE07.10-P-2505-97D
		Engine 139 in model 118, 177, 247	PE07.10-P-2505-97E
		Engine 254 in model 206, 254 Engine 256 in model 223	PE07.10-P-2505-97F
		Engine 176 in model 223	PE07.10-P-2505-97G
		Engine 279 in model 223	PE07.10-P-2505-97H
		Engine 139 in model 206, 232	PE07.10-P-2505-97I
		Engine 654 in model 206, 254 Engine 656 in model 223	PE07.10-P-2505-97J
		Engine 177 in model 223, 232	PE07.10-P-2505-97K
		Engine 656 in model 464	PE07.10-P-2505-97L
	Function schematic for ignition OFF	Engine 608 in model 118, 177, 247	PE07.10-P-2506-97A
		Engine 176, 177 in model 167 Engine 177 in model 290 as of model year 2021	PE07.10-P-2506-97B
		Engine 260, 282 in model 118, 177, 247 Engine 264 in model 167	PE07.10-P-2506-97C
		Engine 654 in model 118, 167, 177, 247 Engine 654 in model 213, 238, 257 as of model year 2021 Engine 656 in model 167	PE07.10-P-2506-97D
		Engine 139 in model 118, 177, 247	PE07.10-P-2506-97E
		Engine 139 in model 206, 232	PE07.10-P-2506-97F
		Engine 254 in model 206, 254 Engine 256 in model 223	PE07.10-P-2506-97G
		Engine 176 in model 223	PE07.10-P-2506-97H
		Engine 279 in model 223	PE07.10-P-2506-97I
		Engine 654 in model 206, 254 Engine 656 in model 223	PE07.10-P-2506-97J
		Engine 177 in model 223, 232	PE07.10-P-2506-97K
		Engine 274 in model 213 as of model year 2021	PE07.10-P-2506-97L
		Engine 656 in model 464	PE07.10-P-2506-97M
	Additional basic functions
	Combustion engine control unit, basic function		GF07.08-P-9890A